Mexico's northern states of Sonora and Chihuahua are bracing for more rough weather.

At least 63 municipalities in Mexico's northern Sonora state have declared a state of emergency amid fierce storms and unusually cold weather as of Monday.

Snow blanketed much of Sonora's north over the weekend, with temperatures dropping as a cold front moved across the state.

“The cold front is entering through the northern part of the state … and causing significant drops in temperature in the central part (of the state) and south,” said Alberto Flores Chong, the coordinator of the state emergency service UEPC.

Emergency officials have urged residents to brace for worse weather, as storms continue to whip much of Mexico's north.

Some municipalities in the north have reported temperatures dropping as low as minus 17 degrees Celcius.

In the neighboring state of Chihuahua, Ciudad Juarez has seen at least 30 centimeters of snow, and roads have been closed in some parts of the state.